Clutch control mechanism



0V 5 i935. M. wlNDELlNcKx CLUTCH CONTROL MECHANISM Filed May 12, 1930 Patented Nov. 5, 1935 NITED STATES PATENT OFFICE Application May 12, 1930, Serial No. 451,760 In France May 15, 1929 1 Claim.

My invention relates to an automatic device for operating the clutch mechanism of a mechanically propelled vehicle.

In motor vehicles or other means of locomotion 5 the object of the clutch is to couple or uncouple an engine to the transmission. This clutch is generally actuated by a pedal or by a lever.

The object of the present invention is to suppress this effort by providing a device making use of the vacuum existing in the intake manifold of an internal combustion engine.

According to the invention the pressure variations which occur in such a reduced pressure system according to the operating conditions of the engine are employed to actuate a distributor valve which serves to connect a vacuum servomotor, for moving the clutch mechanism, either to a reduced pressure system or to the atmosphere.

The invention will be more particularly described with reference to the accompanying drawing, in which Figures 1 and 2 are sectional views representing two working positions of a preferred construction of the device.

When an engine is running at a normal driving speed, the throttle of the Carburettor being partly or entirely open, the degree of vacuum in the induction piping does not differ very greatly from the atmospheric pressure. On the contrary,

when the engine is running at slow speed, the said vacuum is considerably increased, owing toy the fact that the throttle of the Carburettor is in its extreme position of closing. Using this fact as a basis, it is possible to construct an automatic distributor which by connecting a vacuum servomotor coupled to the clutch mechanism to the intake-manifold, will cause declutching as soon as the engine slows down.

Such a distributor consists of a cylinder I8, in

which a piston I9 slides. The said piston is provided with an air port 20 and a vacuum port 2l, which may, respectively, communicate at certain moments with an air port 23 and a vacuum port 22 leading to the servo-motor cylinder 4. An airtight wall 26 of the piston I9 divides the cylinder vI8 into two distinct chambers 21 and 23. The chamber 2l communicates with the source of vacuum by the pipe 1. The chamber 28 is subjected to atmospheric pressure by the oriiice 8.

A spring 24, suitably calibrated, normally maintains the piston I9 in a position such that the port 2l! communicates With the port 23, establishing atmospheric pressure in the interior of the cylinder 4 (clutching period, Fig. l).

When the throttle is closed and the engine slows down the value of the vacuum in the chamber 21 increases in proportions suicient to draw back the piston I9, while overcoming the action of the spring 24. The said piston closes the port 23 and uncovers the port 22, establishing in the cylinder 4 the vacuum existing in the chamber 2l and the pipe 1. The declutching piston 9 is then compelled to move in the direction provided for eiecting declutching (Fig. 2).

When opening the throttle, the degree of vac- 5 uum falls, and the distributor piston I9 takes up its initial position owing to the spring 24, closes the port 22 and uncovers the air port 23. The clutch is again engaged. A slotted slide 25 in the connecting rod II enables clutching and de- 10 clutching to be effected by the foot of the operator in the usual manner, without moving the parts constituting the automatic clutching mechanism, provided the declutching pedal I0 is retained. l5

A detachable nozzle 8a on the air inlet 8 and nut 'Ia in the vacuum pipe 1 enable calibrated openings of different diameters to be provided, which give an adjustment insuring a more or less rapid movement of the piston B in the cylinder 4, 20 which adjustment is determined by experiment according to the strength of the clutch springs.

The invention thus covers the principle of automatic declutching by the sole effect of the increase in vacuum in the induction piping of the 25 engine when communication between the said piping and the Carburettor has been throttled sufficiently by releasing the accelerated peda partly or entirely.

What I claim is: 30

In an automatic clutch operating mechanism for motor vehicles having a source of vacuum, a servo-motor cylinder, a servo-motor piston in the cylinder connected to the clutch operating member, a distributor device for controlling the par- 35 tial vacuum in the servo-motor cylinder, said distributor device comprising a casing and a distributing member movable therein, and having a surface subjected to the sub-atmospheric pressure of the source of vacuum and a second surface 40 subjected to the pressure of the atmosphere, a resilient means acting upon the said rst mentioned surface in a direction opposite to that of the sub-atmospheric pressure, a vacuum inlet port between the servo-cylinder and the dis- 45 tributor casing, a vacuum inlet port on the distributor member to register with said iirst mentioned vacuum inlet port after displacement of said distributing member, under the action of increase of vacuum in the vacuum source when 50 the carbureter throttle is in its closing position, an air inlet port between the servo-cylinder and the distributor casing, and an air inlet port in said distributing member to register with said rst mentioned air inlet port after displacement 55 of said distributing member under the action of said resilient means when the degree of vacuum is decreased, due to the opening of the throttle valve.

MAURICE WINDELNCKX. no 

